The invention pertains to a clamping system with a clamping nut and a wrench for tightening the clamping nut, to a mechanical clamping element, and to the use of an undercut profile.
Various mechanical clamping elements are already known. Clamping nuts are used, for example, to clamp collet chucks, which are used to clamp tool shafts in the tool holder of a machine tool. Especially in cases where space is limited and access to the clamping element is narrow, special measures must be taken to ensure that the necessary force for clamping can be exerted. In the conventional method, clamping is carried out with a wrench, which, for example, is equipped with pins, which engage in hole-like recesses in the clamping nut, so that the wrench can be used to tighten the clamping nut. German Utility Model DE 296 08 677 U1 describes, for example, a clamping nut with slot-like recesses, in which the pins of a wrench can engage.
To prevent the wrench from slipping off, European Patent Application EP 1 052 047 A2 describes a clamping nut which provides groove-like recesses for the engagement of the pins arranged on a clamping wrench. The grooves are formed with a dovetail-shaped cross section, so that the pins of the wrench, the profile of which is complementary to that of the grooves, can grip the undercut of the grooves, which prevents the wrench from sliding off. Undercuts of other types have also already been described. Thus, for example, German Application Publication No. DE 103 02 529 A1 describes a comparable clamping nut, in which the grooves comprise an undercut with an S-shaped profile. It is true that, as a result of the undercut profile of the grooves, it is possible to stabilize the nut on the wrench to a certain degree, but it is still impossible to prevent the nut from sliding laterally off the wrench under all conditions. As a solution to this problem, German Utility Model DE 201 19 008 U1 proposes that the collar of the clamping nut be provided with a separate locking ring, which is intended to prevent the wrench from shifting or sliding laterally out of the grooves. This separate element for locking the nut, however, is complicated and cumbersome in practice and is therefore not a suitable way of solving the problem.